Blade release and switch inactivating means for power operated knife



H. KORSHAK BLADE RELEASE AND SWITCH INACTIVATING MEANS FOR POWEROPERATED KNIFE May 30, 1967 2 Sheets-Sheet 1 Filed Oct. 4, 1965INVENTOR. HARVEY KORSHAK ATTORNEY v May 30, 1967 KORSHAK 3,322,925

BLADE RELE AND SWITCH INACTIV .NG

MEANS FOR POWER OPERATED KNIF' Filed Oct. 4, 1965 I 2 Sheets-Sheet 2 33k INVENTOR. 53 H HARVEY KORSHAK 3! I BY Fig-J5 73% ATTORNEY UnitedStates Patent 3,322,925 BLADE RELEASE AND SWITCH INACTIVATING MEANS FORPOWER OPERATED KNIFE Harvey Korshak, Skokie, Ill., assignor to ScovillManufacturing Company, Waterbury, Conn., a corporation of ConnecticutFiled Oct. 4, 1965, Ser. No. 492,641 7 Claims. (Cl. 200-157) Thisinvention relates to power operated knives, and more particularly toblade release and switch inactivating means for electric knives.

Power operated knives are provided with depressible blade releasebuttons and with electric switch actuating buttons usually located onopposite sides of the knife handles. When the user depresses the bladerelease button for removing the blades from the handle, there islikelihood of accidental actuation of the switch actuating means whichenergizes the motor and results in reciprocatory movements of the bladesand possible injury to the user.

The main object of the invention is to provide blade release meansoperatively connected to mechanism which automatically renders theelectric switch inactive while the blade release button is depressed,thereby preventing energizing of the motor and consequent unintendedreciprocatory movement of the knife blades.

The object of the invention is achieved bymechanism operativelyassociated with the blade release button, and designed to separate theswitch contacts and. hold the contact in non-engaging position while theblade release button is depressed.

The switch inactivating means consists of a single lever, simple inconstruction and dependable in operation for its intended purpose.

In the drawings:

FIG. 1 is a longitudinal vertical sectional view of part of a poweroperated knife handle and mechanism located therein, partly inelevation, on an enlarged scale, showing my invention.

FIG. 2 is a horizontal sectional view in the plane of the line 2-2 ofFIG. 1.

FIG. 3 is a fragmentary vertical sectional view in the plane of the line33 of FIG. 2, showing the switch mechanism in switch closing position,and the blade release button in its normal non-depressed position.

FIG. 4 is a transverse vertical sectional view in the plane of theline44 of FIG. 3.

FIG. 5 is a view similar to FIG. 3, showing the blade release button indepressed position and the switch contacts in non-engaging positionsnotwithstanding depression of the switch actuating button.

FIG. 6 is a transverse vertical sectional view in the plane of the line6-6 of FIG. 5.

In that embodiment of the invention shown in the drawings, a housing 10encloses a motor 11, motor shaft 12, driver bars 13, 13 connected toblade carriers 14, 14, and driving mechanism located between the motorand the driver bars for imparting reciprocatory motion to the driverbars and carriers. Tangs 15, 15 of knife blades (not shown) are mountedin and retained by the carriers 14.

The driving mechanism comprises a pinion and spacer 19 fixed on themotor shaft 11, the pinion meshing with a bevel gear 21 formedintegrally with hub 22 provided with cranks 23, 24 at opposite ends forengaging the openings 25 in driver bars 13 and imparting reciprocatorymotion thereto. Further details of the driving mechanism need not bedescribed herein because said mechanism is not the subject of thisinvention.

The motor 11 is energized by switch mechanism which comprises the upperspring 30, lower spring 31, carrying contacts 32, 33, respectively, ontheir free ends, with their 3,322,925 Patented May 30, 1967 "iceopposite ends mounted on a fixed part of the housing by screw 34 andspaced apart by insulation 35. The switch mechanism is actuated by atrigger type button 36 mounted in the lower side of the housing 10,urged to inoperative position by spring 37 bearing at one end againstthe boss 38 on the button and attached at its other end to a part 39 ofthe housing. FIG. 1 shows the switch button 36 in normal undepressedposition and the switch contacts 32, 33, in open switch position. FIG. 3shows the switch button 36in depressed, switch closing position, withthe contact 33 on spring 31 raised by boss 38 into engagement withcontact 32 on spring 30.

A blade release button 40 is mounted in the upper side of the housing10. The button 40 has beveled lower side surfaces 41 for separatingblade carriers 14 to release the blade tangs, and is provided with alongitudinally extending recess 42 into which extends a leaf spring 43which urges the button to maintain its normal raised position shown inFIGS. 1 and 3.

The mechanism which is operatively associated with the blade releasebutton 40 for the purpose of inactivating the switch mechanism when thebutton 40 is depressed comprises a pivot lever 50, as a whole, looselymounted in the housing 10. The lever 50 consists of an upper arm 51 incontact with the leaf spring 43 in recess 42 of button 40, anddepressib-le by said release button; a lower arm 52 provided with alifting extension 53 for lifting the contact spring 30; and anintermediate member 54 integral with said arms 51, 52. The liftingextension 53 is the projecting end of a depending rib on the lowersurface of the lower arm 52 of the lever 50, which extends through aslot in the upper contact spring 30.

The lever 50 is not positively pivotally mounted, but pivotal motion isimparted to the lever when the blade release button 40 is depressed, andby hearing downwardly on the lever arm 51 the lower arm 52 of the leveris raised. This movement of the lever lifts the upper contact spring 30and holds the contact32 out of contact with contact 33 even when thecontact spring 31 and contact 33 thereon are raised by actuation ofswitch button 36. As soon as the blade release button 40 is relieved ofpressure, it retains to normal position under influence of spring 43,and then the switch contacts 32, 33, can close in response to theactuation of the switch button 36.

The lever 50 is held in intended position laterally by the location ofthe arm 51 in the recess 43 and by the engagement of the depending rib53 in the slotted contact spring 30 while the projecting end of the rib53 underlies the spring 30 for lifting it when the blade release buttonis depressed.

Changes may be made in details of construction and in the form andarrangement of parts without departing from the scope of the invention.Obviously, the embodiment of the invention need not be confined to powerope-rated knives. The invention may be used in any motor driven toolprovided with a tool release button and electric switch actuating means.

I claim:

1. In a powerv operated knife, blade release and switch inactivatingmeans comprising (a) a housing,

(b) carriers in the housing in which blade tan'gs are releasablymounted,

(c) a blade release button means depressibly mounted in the housing forseparating the blade tangs and carriers,

(d) electric switch mechanism including a pair of spaced apart contactcarrying springs and a switch button 'means depressibly mounted in thehousing for moving one of said contact carrying springs relatively tothe other into switch closing position, and

(e) a pivotal lever having a first arm engaged by the blade releasebutton and a second arm engaging one of said contact carrying springs,actuation of said lever arms by depression of the release button causingmovement of said arm-engaged contact carrying spring into open switchposition during depression of the blade release button for inactivatingthe switch regardless of whether the other contact carrying spring is inswitch closing position.

2. The blade release and switch inactivating means for a power operatedknife defined by claim 1, in which the blade release button is providedwith a recess, and the first arm of the pivotal lever is located in therecess and laterally confined therein by the recess side surfaces.

3. The blade release and switch inactivating means for a power operatedknife defined by claim 1, which includes a leaf spring bearing at oneend on an inner surface of the housing adjacent the blade release buttonand having its other end located in a recess in the button for urgingthe button into non-depressed position in the housing.

4. The blade release and switch inactivating means for a power operatedknife defined by claim 1, in which the arm-engaged contact carryingspring is provided with a slot, and the lever second arm has a dependingrib extending through the slot and a projection on one end of the ribfor engaging the spring adjacent the slot.

5. The blade release and switch inactivating means for a power ope-ratedknife defined by claim 1, in which the pivotal lever includes anintermediate member integral with said first and second arms, and saidarms extend from the intermediate member at right angles thereto.

6. In a power operated knife, blade release and switch inactivatingmeans comprising (a) a housing,

(b) carriers mounted in the housing for reciprocal movement and havingblade tangs releasably mounted therein,

(c) a blade release button means depressibly mounted in the upper wallof the housing for separating the blade tangs and carriers,

(d) electric switch mechanism including a pair of vertically spacedapart contact carrying leaf springs 4 and a switch button meansdepressibly mounted in the lower wall of the housing for moving thelower one of said contact carrying springs upwardly into contact withthe other spring for closing the switch, and (e) a pivotal lever havinga first arm engaged by the blade release button and a second armengaging the upper one of said contact carrying springs, actuation ofsaid lever arms by depression of the release button causing liftingaction by said second arm and movement of the upper spring into openswitch position during depression of the blade release button forinactivating the switch regardless of whether the lower contact carryingspring is in switch closing position. 7. In a power ope-rated applianceprovided with an actuated tool, the improvement which comprises (a) ahousing,

(b) a tool carrier in the housing, 7 (c) a tool release button meansdepressibly mounted in the housing for separating the tool and carrier,(d) electric switch mechanism including a pair of spaced apart contactcarrying springs and a switch button means depressibly mounted in thehousing for moving one of said contact carrying springs relatively tothe other into switch closing position, and

(e) a pivotal lever having a first arm engaged by the tool releasebutton and a second arm engaging one of said contact carrying springs,actuation of said lever arms by depression of the release button causingmovement of said arm-engaged contact carrying spring into open switchposition during depression of the tool release butt-on for inactivatingthe switch regardless of whether the other contact carrying spring is inswitch closing position.

No references cited.

ROBERT K. SCHAEFER, Primary Examiner.

H. BURKS, Assistant Examiner.

1. IN A POWER OPERATED KNIFE, BLADE RELEASE AND SWITCH INACTIVATINGMEANS COMPRISING (A) A HOUSING, (B) CARRIERS IN THE HOUSING IN WHICHBLADE TANGS ARE RELEASABLY MOUNTED, (C) A BLADE RELEASE BUTTON MEANSDEPRESSIBLY MOUNTED IN THE HOUSING FOR SEPARATING THE BLADE TANGS ANDCARRIERS, (D) ELECTRIC SWITCH MECHANISM INCLUDING A PAIR OF SPACED APARTCONTACT CARRYING SPRINGS AND A SWITCH BUTTON MEANS DEPRESSIBLY MOUNTEDIN THE HOUSING FOR MOVING ONE OF SAID CONTACT CARRYING SPRINGSRELATIVELY TO THE OTHER INTO SWITCH CLOSING POSITION, AND (E) A PIVOTALLEVER HAVING A FIRST ARM ENGAGED BY THE BLADE RELEASE BUTTON AND ASECOND ARM ENGAGING ONE OF SAID CONTACT CARRYING SPRINGS, ACTUATION OFSAID LEVER ARMS BY DEPRESSION OF THE RELEASE BUTTON CAUSING MOVEMENT OFSAID ARM-ENGAGED CONTACT CARRYING SPRING INTO OPEN SWITCH POSITIONDURING DEPRESSION OF THE BLADE RELEASE BUTTON FOR INACTIVATING THESWITCH REGARDLESS OF WHETHER THE OTHER CONTACT CARRYING SPRING IS INSWITCH CLOSING POSITION.